<P><B>Abstract</B></P> <P>Turion is a kind of dormant tissue from <I>Spirodela polyrrhiz</I>a (L) Schleid and represents another duckweed-based starch production system, which owns several potential technical merits than the conventional one. This paper systematically investigated the physiological, biochemical and production characteristics of turion and preliminarily evaluate its feasibility for bioethanol production. Turion productivity of 3.78 g/m<SUP>2</SUP>/d and starch productivity of 2.90 g/m<SUP>2</SUP>/d was achieved in strain 0196. Full-component analysis revealed that turion is high-quality substrate as it contained high starch content (65.63%) and low lignocellulose content (12.82%). Besides, turion can be continuously produced by strain 0196 up to 6 weeks, indicating a sustainable manufacture of them is possible. Finally, harvested turion was used for ethanol fermentation for the first time with an ethanol yield of 0.34 g g<SUP>−1</SUP>(turion), resulted in an annual yield of 4.69 t/ha. This research elucidated that turion from duckweed is a novel biomass for biofuel production.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Turion is a dormant tissue from duckweed and has promising bioenergy prospect. </LI> <LI> Whole-composition analysis revealed that turion is high-quality biofuel feedstock. </LI> <LI> Turion can be consecutively produced over one month without nutrients supplement. </LI> <LI> Ethanol yield of 0.34 g g<SUP>−1</SUP>(turion) was achieved with conversion rate of 91.67%. </LI> <LI> An innovative and economical duckweed-based starch production mode was established. </LI> </UL> </P>